Comparison of methyltransferase activities of pair-fed rats given adequate or methyl-deficient diets

The short-term effects of a lipotrope-deficlent (methyl-deficient)diet on tRNA and protein methyltransferase activities have beenstudied using pair-fed male Fischer rats. The activity of liverN2-guanine tRNA methyltransferase II (NMG2) of animals receivingthe methyl-deficient diet (MDD) for 2 weeks was found to beelevated more than 2-fold. This is in agreement with the resultsof earlier experiments in which the animals were fed ad libitum.These data indicate that the effects of lipotrope-deficientdiets on NMG2 activity observed in the earlier studies can beattributed to the nature of the diet, and not to differencesin caloric intake. In the same pair-fed animals, very littleeffect of MDD on the activity of NMG2 of either brain or spleenwas observed. In liver, the activity of one of the enzymes thatcatalyze protein methylation-protein methylase I (S-adenosyl-methionine:protein-arginine N-methyltransferase)-was significantly elevatedin response to the lipotrope-deficient diet. In contrast, theactivities of protein methylase II (S-adenosylmethionine: protein-carboxyO-methyltransferase), from control and experimental animalsdid not differ significantly. Lipotrope-deficient diets arethus seen to induce, within a short period of time, selectivechanges in the activities of some, but not all, of the liverenzymes that catalyze the methylation of tRNA and protein.     

The former transsexual: A case study

The case is presented of a biological male, diagnosed as transsexual, who lived as a female for a considerable period and then returned to the male role. The subject came within days of having genital surgery, deciding to return to the male role after surgery was canceled due to policy changes at a hospital. A number of factors are offered as possible correlatives to the decision to return to the original gender role. These include increase in assertiveness, decrease in gender-role stereotyping, religious conversion, improvement of vocational state, and falling in love. It is suggested that the original diagnosis of transsexualism is not invalidated by the subject's subsequent decision. The relationship between personality characteristics such as passivity and the tendency of such clients to apply rigid stereotypes to gender is discussed. The importance of an extended trial period prior to genital surgery is reinforced by the present case, and it is suggested that increased attention be given to gender-role stereotyping among sex reassignment candidates.This is an expanded version of a paper presented at the Sixth International Gender Dysphoria Symposium, San Diego, California, February 1979.     

APPRAISAL OF LONGEVITY AND CONSIDERATION OF A NEW PARAMETER

The advanced ages and good health of many of the surviving members of the longitudinal study known as “Operation Retirement” prompted the researchers to initiate a study of longevity. One hundred and eleven subjects were interviewed intensively (average age 80) and life-data and information of psychological concern were collated concerning panel members and their siblings and ancestors. Age at death and causes of death were generally reliably reported from family records, variously reaching back through two or three generations. Methodological problems caused the investigators to seek a new parameter, which they have called the Longevity Quotient (LQ), in some ways analogous to the Age-Resistance Quotient established in relation to the UQOR retirement recreation guidance tests. For this purpose, a tabulation of life-expectancy at birth had to be compiled, beyond the earliest birth dates available in the official Australian records. This will be discussed, in the explanation of the formula: Longevity Quotient (LQ) = Age of death/Life Expectancy at birth × 100 Since the LQ cannot properly be estimated until death, the method has had to be applied tentatively in respect of panel members, but firmly in a comparison of IQs and LQs of deceased members of the panel.     

Fusion of LLC-MK2 tissue culture cells induced by measles virus

Summary Fusion of measles infected LLC-MK₂ cells may occur before cytopathic lesions have developed as well as in later stages of infection when cytopathic lesions are prominent. The fusion process follows a sequence and requires an active metabolism of the fusing cells. The cell with the larger nuclear mass acts as the host cell. Giant cells induced by different agents are not similar with respect to developmental and structural characteristics. Fusiform-stellate shaped cells do not fuse.Aided by a grant from the National Foundation.     

Reversal of diabetes by pancreatic islet transplantation into a subcutaneous, neovascularized device

BACKGROUND: Transplantation of pancreatic islets for the treatment of type 1 diabetes allows for physiologic glycemic control and insulin-independence when sufficient islets are implanted via the portal vein into the liver. Intrahepatic islet implantation requires specific infrastructure and expertise, and risks inherent to the procedure include bleeding, thrombosis, and elevation of portal pressure. Additionally, the relatively higher drug metabolite concentrations in the liver may contribute to the delayed loss of graft function of recent clinical trials. Identification of alternative implantation sites using biocompatible devices may be of assistance improving graft outcome. A desirable bioartificial pancreas should be easy to implant, biopsy, and retrieve, while allowing for sustained graft function. The subcutaneous (SC) site may require a minimally invasive procedure performed under local anesthesia, but its use has been hampered so far by lack of early vascularization, induction of local inflammation, and mechanical stress on the graft. METHODS: Chemically diabetic rats received syngeneic islets into the liver or SC into a novel biocompatible device consisting of a cylindrical stainless-steel mesh. The device was implanted 40 days prior to islet transplantation to allow embedding by connective tissue and neovascularization. Reversal of diabetes and glycemic control was monitored after islet transplantation. RESULTS: Syngeneic islets transplanted into a SC, neovascularized device restored euglycemia and sustained function long-term. Removal of graft-bearing devices resulted in hyperglycemia. Explanted grafts showed preserved islets and intense vascular networks. CONCLUSIONS: Ease of implantation, biocompatibility, and ability to maintain long-term graft function support the potential of our implantable device for cellular-based reparative therapies.     

Reliability and Validity of the Smoking and Women Questionnaire among Three Ethnic Groups

Abstract Cigarette smoking among women continues to be a major health risk to the smoker and to those around her. Programs aimed at stopping and maintaining smoking cessation have had very limited success due in part to the failure to individualize smoking cessation programs based on specific characteristics of the smoker. This study presents reliability and validity of a 14-item questionnaire developed to determine the readiness of women from three ethnic groups (non-Hispanic white, black American, and Hispanic American) to stop smoking. The Smoking and Women Questionnaire (SWQ) consists of items representative of core elements conceptualized in the Smoking/Ex-smoking Model for Women. The core factors are: beliefs/attitudes toward smoking, sociability, stress, coping, self-efficacy, motivation, nicotine dependence, and support. The SWQ was completed by both smoking and nonsmoking non-Hispanic white ( N = 233), smoking and nonsmoking black American ( N = 70), and smoking and nonsmoking Hispanic American ( N = 73) women. The test-retest correlation coefficient over a one- to three-week period ( N = 53) was .84. Cronbach alphas for whites, blacks, Hispanics, and combined groups were .81, .85, .84, and .83, respectively. Content validity was shown by experts who agreed that the core elements were represented in the SWQ. Construct validity was shown for ethnic groups separately and combined in that smokers had significantly lower SWQ scores than non-smokers. Items representative of the core elements were rated by smokers in a similar manner irrespective of ethnicity, suggesting similar attitudes and behaviors toward smoking. Further research is needed to determine if the SWQ can predict readiness of women to stop smoking and serve as a basis for developing individualized smoking cessation programs. Implications for smoking cessation programs are reviewed.     

Valproic acid modulates NCAM polysialylation and polysialyltransferase mRNA expression in human tumor cells

Polysialic acid (PSA) is a dynamically regulated carbohydrate modification of the neural cell adhesion molecule NCAM, which has been linked to cancer development and dissemination. Two enzymes, the polysialyltransferases ST8SiaIV and ST8SiaII, are known to be involved in the polysialylation of NCAM. The antiepileptic drug valproic acid (VPA) is associated with anti-cancer activity. In this study, VPA blocked the adhesion of several neuroectodermal tumor cell lines to human umbilical vein endothelial cells. Furthermore, VPA induced intracellular PSA accumulation and enhanced expression of PSA-NCAM on the cell surface. Using a semiquantitative RT-PCR strategy, VPA was shown to up-regulate ST8SiaIV mRNA, whereas ST8SiaII mRNA was down-regulated by this compound. Our data indicate that increased expression of ST8SiaIV enables accelerated polysialylation of NCAM, which might be coupled to a loss of adhesive functions of tumor cells.     

Frontal eye field microstimulation induces task-dependent gamma oscillations in the lateral intraparietal area

Macaque frontal eye fields (FEF) and the lateral intraparietal area (LIP) are high-level oculomotor control centers that have been implicated in the allocation of spatial attention. Electrical microstimulation of macaque FEF elicits functional magnetic resonance imaging (fMRI) activations in area LIP, but no study has yet investigated the effect of FEF microstimulation on LIP at the single-cell or local field potential (LFP) level. We recorded spiking and LFP activity in area LIP during weak, subthreshold microstimulation of the FEF in a delayed-saccade task. FEF microstimulation caused a highly time- and frequency-specific, task-dependent increase in gamma power in retinotopically corresponding sites in LIP: FEF microstimulation produced a significant increase in LIP gamma power when a saccade target appeared and remained present in the LIP receptive field (RF), whereas less specific increases in alpha power were evoked by FEF microstimulation for saccades directed away from the RF. Stimulating FEF with weak currents had no effect on LIP spike rates or on the gamma power during memory saccades or passive fixation. These results provide the first evidence for task-dependent modulations of LFPs in LIP caused by top-down stimulation of FEF. Since the allocation and disengagement of spatial attention in visual cortex have been associated with increases in gamma and alpha power, respectively, the effects of FEF microstimulation on LIP are consistent with the known effects of spatial attention.     

Effects of dance on physical and psychological well-being in older persons

This study was aimed at determining the effects of dancing on the health status of older persons. A pool of 111 community-dwelling subjects were allocated to either an intervention group (IG), which included 23 sessions of dance over 12 weeks, or a control group (CG). All participants were assessed at baseline and 12 weeks. Physical outcome measures included the 6-min timed walking test (6MWT), trunk flexibility, body composition, lower limb endurance and strength, balance, the timed up-and-go test (TUG), resting heart rate and blood pressure. Quality of life was assessed by the Medical Outcomes Survey Short Form (SF-36) questionnaire. The IG's views toward dancing were also evaluated at 12 weeks. Significant difference was observed between the groups in six outcome measures: mean change in resting heart rate, 6MWT, TUG, lower limb endurance and the 'general health' and 'bodily pain' domains of SF-36. The majority of the dance group felt the intervention improved their health status. These findings demonstrate that dancing has physical and psychological benefits, and should be promoted as a form of leisure activity for senior citizens.